In order to protect personnel from falls when working at height it is usual and often a legal requirement, to provide an elongate safety line running across a length of the area in which the personnel are to work. The personnel are attached to the safety line by a lanyard which is provided with a traveller to which the lanyard is secured. The traveller is fixed to the safety line such that it can travel along the safety line. The flexible lanyard is connected at its other end to a harness worn by the user. When connected the user can move with respect to the safety line, tension on the lanyard as the user moves causes the traveller to be dragged to move along the safety line.
The safety line is anchored at each end. In order to allow a long uninterrupted length of safety line a number of intermediate supports are typically provided to support the safety line at predetermined positions along its length. The traveller and supports are designed to cooperate such that the traveller can automatically pass the along the safety line past the intermediate supports with the minimum of interference or drag. The supports are typically in the form of metal brackets which are secured or anchored either into specifically designed support posts or into anchor sockets or points provided integrally in structures such as masonry walls or welded to steelwork
Such a safety line system having intermediate supports and a traveller arranged to pass along the safety line past the intermediate supports is disclosed in for example WO02/092171. In the system disclosed the intermediate supports are provided with deflector or guide surfaces arranged to abut the traveller on approach to the intermediate support so as to re-orientate the traveller to enable smooth passage past the intermediate support.
In so called horizontal systems (often used on roof top structures) the safety line is typically positioned at waist height and the user often lifts the lanyard held in one hand when walking adjacent the safety line. The intermediate brackets are typically mounted upon support posts and may for example be fixed by means of a screw threaded bolt passing through an aperture in a flange portion of the support bracket. In such an arrangement the top of the support post would typically be provided with a screw threaded docking bore to receive the threaded shaft of the bolt for securing the bracket.
An alternative prior art arrangement is shown in FIGS. 1A and 1B. The bracket 101 comprises a D ring fixing 102 for securing to a post 115 or other structure. The top of the post is provided with a threaded bore for accepting the threaded shaft of a fixing bolt 105. The D ring fixing 102 is first positioned on the post and the bolt is then inserted and tightened to secure the D ring fixing 102 and the hanger 103 to the post. The safety line (which is typically a metal cable 116) passes through the hanger 103 and is tensioned.